From: Lars Ellenberg <lars.ellenberg@linbit.com>
To: Jens Axboe <axboe@kernel.dk>,
linux-kernel@vger.kernel.org, linux-block@vger.kernel.org
Cc: drbd-dev@lists.linbit.com
Subject: [PATCH 11/17] drbd: avoid spurious self-outdating with concurrent disconnect / down
Date: Thu, 20 Dec 2018 17:23:38 +0100 [thread overview]
Message-ID: <20181220162344.8430-12-lars.ellenberg@linbit.com> (raw)
In-Reply-To: <20181220162344.8430-1-lars.ellenberg@linbit.com>
If peers are "simultaneously" told to disconnect from each other,
either explicitly, or implicitly by taking down the resource,
with bad timing, one side may see its disconnect "fail" with
a result of "state change failed by peer", and interpret this as
"please oudate yourself".
Try to catch this by checking for current connection status,
and possibly retry as local-only state change instead.
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
---
drivers/block/drbd/drbd_nl.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 1958eb33b643..82915880c5e9 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -2711,8 +2711,10 @@ int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
static enum drbd_state_rv conn_try_disconnect(struct drbd_connection *connection, bool force)
{
+ enum drbd_conns cstate;
enum drbd_state_rv rv;
+repeat:
rv = conn_request_state(connection, NS(conn, C_DISCONNECTING),
force ? CS_HARD : 0);
@@ -2730,6 +2732,11 @@ static enum drbd_state_rv conn_try_disconnect(struct drbd_connection *connection
break;
case SS_CW_FAILED_BY_PEER:
+ spin_lock_irq(&connection->resource->req_lock);
+ cstate = connection->cstate;
+ spin_unlock_irq(&connection->resource->req_lock);
+ if (cstate <= C_WF_CONNECTION)
+ goto repeat;
/* The peer probably wants to see us outdated. */
rv = conn_request_state(connection, NS2(conn, C_DISCONNECTING,
disk, D_OUTDATED), 0);
--
2.17.1
next prev parent reply other threads:[~2018-12-20 16:39 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-20 16:23 [PATCH 00/17] DRBD updates for 4.21 Lars Ellenberg
2018-12-20 16:23 ` [PATCH 01/17] drbd: narrow rcu_read_lock in drbd_sync_handshake Lars Ellenberg
2018-12-20 16:23 ` [PATCH 02/17] drbd: must not use connection after kref_put(&connection->kref) Lars Ellenberg
2018-12-20 16:23 ` [PATCH 03/17] drbd: centralize printk reporting of new size into drbd_set_my_capacity() Lars Ellenberg
2018-12-20 16:23 ` [PATCH 04/17] drbd: ignore "all zero" peer volume sizes in handshake Lars Ellenberg
2018-12-20 16:23 ` [PATCH 05/17] drbd: disconnect, if the wrong UUIDs are attached on a connected peer Lars Ellenberg
2018-12-20 16:23 ` [PATCH 06/17] drbd: fix confusing error message during attach Lars Ellenberg
2018-12-20 16:23 ` [PATCH 07/17] drbd: attach on connected diskless peer must not shrink a consistent device Lars Ellenberg
2018-12-20 16:23 ` [PATCH 08/17] drbd: reject attach of unsuitable uuids even if connected Lars Ellenberg
2018-12-20 16:23 ` [PATCH 09/17] drbd: fix comment typos Lars Ellenberg
2018-12-20 16:23 ` [PATCH 10/17] drbd: do not block when adjusting "disk-options" while IO is frozen Lars Ellenberg
2018-12-20 16:23 ` Lars Ellenberg [this message]
2018-12-20 16:23 ` [PATCH 12/17] drbd: fix print_st_err()'s prototype to match the definition Lars Ellenberg
2018-12-20 16:23 ` [PATCH 13/17] drbd: don't retry connection if peers do not agree on "authentication" settings Lars Ellenberg
2018-12-20 16:23 ` [PATCH 14/17] drbd: skip spurious timeout (ping-timeo) when failing promote Lars Ellenberg
2018-12-20 16:23 ` [PATCH 15/17] drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire") Lars Ellenberg
2018-12-20 16:23 ` [PATCH 16/17] drbd: Avoid Clang warning about pointless switch statment Lars Ellenberg
2018-12-20 16:23 ` [PATCH 17/17] drbd: Change drbd_request_detach_interruptible's return type to int Lars Ellenberg
2018-12-20 16:27 ` [PATCH 00/17] DRBD updates for 4.21 Jens Axboe
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